ApacheManSlim60
Don't know if there is a cover for this but it appears that it is factory (at least the location). According to the 1960-1966 Chev/GMC truck factory assembly instruction manual on page 125 and 128 (I numbered the pages on mine starting with 1 on the page that identifies 1953 thru 1959 vehicle serial number identification [not sure why that is in this manual]).
